Atom DTU NB-IoT2 issues.

felmue

no, it is not possible to reset/reboot SIM7028 from M5AtomS3 due to the fact that RESET pin is not connected.

There is an AT command to reset SIM7028, but if it is stuck that probably doesn't work. The other way is pulling RESET pin low, but that doesn't help as long as RESET pin isn't connected.

If you don't need the built-in RS485 or the built-in Groove port you could rewire one of those GPIOs via transistor to the RESET pin. (But make sure you use the appropriate circuit / level shifter.)

From SIM7028 Hardware Design document:

"3.2.1 Power on
The module is automatically turned on after power on, without a power button. Under the condition that the RESET pin is not pulled low by the outside, the module will automatically power on after supplying a voltage of 2.2V to 4.3V to the VBAT pin."

"3.2.2 Power off
The module can be shut down by disconnecting the VBAT power supply."

"3.2.3 Reset Function
SIM7028 can reset the module by keeping the RESET pin low for at least 50ms. The module can also be reset by the AT command "AT+NRB".
The RESET signal has been pulled up inside the chip, and the RESET signal will immediately change to a high level after the module is powered on."

Edit: I just tried the AT command to reset the module, but all I get back is ERROR and nothing happens.

Thanks
Felix

cocoa

Hello @felmue ,

Thank you for informations and suggestions.

For me it is clear that the module must be used as a product and sold, so I hope that the AT reset command will solve any stuck of the modem.

M5stack has not yet released the examples in UIFLOW2 for this module, so the module is useless for those who want to use UIFlow2. The ones for Atom DTU UIFlow1 obviously don't work.

I just can't use it with Arduino / Platformio too.

Could you share your source code to make a http connection? It would be of great help to me to get out of this impasse.

Thx.

felmue

Hello @cocoa

the http example from here is working for me with the one modification in TinyGSM I mentioned.

You haven't shared the log with #define DUMP_AT_COMMANDS enabled - this might shed some light onto what going on at your end.

I guess you haven't noticed my edited note above about the AT reset command AT+NRB which did not work for me. All I got was an ERROR.

Here you can find my modification to reset SIM7028 via GPIO.

BTW: have you ever tried to check the firmware version currently installed on your SIM7028? E.g. AT+CGMR? Maybe it needs an upgrade?

Thanks
Felix

cocoa

Hi @felmue, sorry for delay.

Here is the log with #define DUMP_AT_COMMANDS enabled .



         Connected!
14:23:54.308 > >>ATOM DTU NB MQTT TEST
14:23:54.308 > AT+CICCID
14:23:54.308 > 
14:23:54.308 > ERROR
14:23:54.308 > CCID: ERROR
14:23:54.308 > AT+CSQ
14:23:54.314 > 
14:23:54.314 > +CSQ: 21,0
14:23:54.314 > 
14:23:54.315 > OK
14:23:54.315 > Signal quality: 21
14:23:54.315 > Initializing modem...
14:23:54.315 > [  1689][E][esp32-hal-gpio.c:102] __pinMode(): Invalid pin selected
14:23:54.321 > E (1581) gpio: gpio_set_level(227): GPIO output gpio_num error
14:23:54.621 > E (1881) gpio: gpio_set_level(227): GPIO output gpio_num error
14:23:59.621 > AT
14:23:59.624 > 
14:23:59.624 > OK
14:23:59.624 > ATE0
14:23:59.628 > 
14:23:59.629 > OK
14:23:59.629 > AT+CFUN=1
14:23:59.636 > 
14:23:59.636 > OK
14:23:59.636 > AT+QCLEDMODE=1
14:23:59.641 > 
14:23:59.641 > OK
14:23:59.641 > AT+CMEE=0
14:23:59.645 > 
14:23:59.645 > OK
14:23:59.645 > AT+CTZR=0
14:23:59.649 > 
14:23:59.649 > OK
14:23:59.649 > AT+CTZU=1
14:23:59.653 > 
14:23:59.653 > OK
14:23:59.653 > AT+CPIN?
14:23:59.660 > 
14:23:59.660 > +CPIN: READY
14:23:59.661 > 
14:23:59.661 > OK
14:23:59.661 > Waiting for network...
14:23:59.661 > AT+CREG?
14:23:59.667 > 
14:23:59.667 > +CREG: 0,0
14:23:59.668 > 
14:23:59.668 > OK
14:23:59.918 > AT+CREG?
14:23:59.924 > 
14:23:59.925 > +CREG: 0,0
14:23:59.925 > 
14:23:59.925 > OK
14:24:00.175 > AT+CREG?
14:24:00.181 > 
14:24:00.181 > +CREG: 0,0
14:24:00.182 > 
14:24:00.182 > OK
14:24:00.432 > AT+CREG?
14:24:00.438 > 
14:24:00.439 > +CREG: 0,0
14:24:00.439 > 
14:24:00.439 > OK
14:24:00.689 > AT+CREG?
14:24:00.694 > 
14:24:00.695 > +CREG: 0,0
14:24:00.695 > 
14:24:00.695 > OK
14:24:00.946 > AT+CREG?
14:24:00.952 > 
14:24:00.952 > +CREG: 0,0
14:24:00.952 > 
14:24:00.952 > OK
14:24:01.203 > AT+CREG?
14:24:01.209 > 
14:24:01.209 > +CREG: 0,0
14:24:01.209 > 
14:24:01.210 > OK
14:24:01.460 > AT+CREG?
14:24:01.466 > 
14:24:01.466 > +CREG: 0,0
14:24:01.467 > 
14:24:01.467 > OK
14:24:01.717 > AT+CREG?
14:24:01.723 > 
14:24:01.724 > +CREG: 0,0
14:24:01.724 > 
14:24:01.724 > OK
14:24:01.974 > AT+CREG?
14:24:01.980 > 
14:24:01.980 > +CREG: 0,0
14:24:01.981 > 
14:24:01.981 > OK
14:24:02.231 > AT+CREG?
14:24:02.237 > 
14:24:02.238 > +CREG: 0,0
14:24:02.238 > 
14:24:02.238 > OK
14:24:02.488 > AT+CREG?
14:24:02.494 > 
14:24:02.494 > +CREG: 0,0
14:24:02.494 > 
14:24:02.495 > OK
14:24:02.745 > AT+CREG?
14:24:02.751 > 
14:24:02.751 > +CREG: 0,0
14:24:02.751 > 
14:24:02.751 > OK
14:24:03.002 > AT+CREG?
14:24:03.008 > 
14:24:03.008 > +CREG: 0,0
14:24:03.009 > 
14:24:03.009 > OK
14:24:03.259 > AT+CREG?
14:24:03.264 > 
14:24:03.265 > +CREG: 0,0
14:24:03.265 > 
14:24:03.265 > OK
14:24:03.516 > AT+CREG?
14:24:03.521 > 
14:24:03.521 > +CREG: 0,0
14:24:03.522 > 
14:24:03.522 > OK
14:24:03.773 > AT+CREG?
14:24:03.779 > 
14:24:03.779 > +CREG: 0,0
14:24:03.779 > 
14:24:03.779 > OK
14:24:04.030 > AT+CREG?
14:24:04.036 > 
14:24:04.036 > +CREG: 0,0
14:24:04.036 > 
14:24:04.036 > OK
14:24:04.287 > AT+CREG?
14:24:04.293 > 
14:24:04.293 > +CREG: 0,0
14:24:04.293 > 
14:24:04.293 > OK
14:24:04.544 > AT+CREG?
14:24:04.549 > 
14:24:04.549 > +CREG: 0,0
14:24:04.550 > 
14:24:04.550 > OK
14:24:04.801 > AT+CREG?
14:24:04.806 > 
14:24:04.806 > +CREG: 0,0
14:24:04.807 > 
14:24:04.807 > OK
14:24:05.058 > AT+CREG?
14:24:05.064 > 
14:24:05.064 > +CREG: 0,0
14:24:05.064 > 
14:24:05.065 > OK
14:24:05.315 > AT+CREG?
14:24:05.321 > 
14:24:05.322 > +CREG: 0,0
14:24:05.322 > 
14:24:05.322 > OK
14:24:05.572 > AT+CREG?
14:24:05.578 > 
14:24:05.578 > +CREG: 0,0
14:24:05.580 > 
14:24:05.580 > OK
14:24:05.829 > AT+CREG?
14:24:05.835 > 
14:24:05.835 > +CREG: 0,0
14:24:05.835 > 
14:24:05.836 > OK
14:24:06.086 > AT+CREG?
14:24:06.091 > 
14:24:06.092 > +CREG: 0,0
14:24:06.092 > 
14:24:06.092 > OK
14:24:06.343 > AT+CREG?
14:24:06.349 > 
14:24:06.349 > +CREG: 0,0
14:24:06.349 > 
14:24:06.350 > OK
14:24:06.600 > AT+CREG?
14:24:06.606 > 
14:24:06.606 > +CREG: 0,0
14:24:06.607 > 
14:24:06.607 > OK
14:24:06.857 > AT+CREG?
14:24:06.863 > 
14:24:06.863 > +CREG: 0,0
14:24:06.864 > 
14:24:06.864 > OK
14:24:07.114 > AT+CREG?
14:24:07.120 > 
14:24:07.121 > +CREG: 0,0
14:24:07.121 > 
14:24:07.121 > OK
14:24:07.371 > AT+CREG?
14:24:07.377 > 
14:24:07.377 > +CREG: 0,0
14:24:07.378 > 
14:24:07.378 > OK
14:24:07.628 > AT+CREG?
14:24:07.634 > 
14:24:07.634 > +CREG: 0,0
14:24:07.635 > 
14:24:07.635 > OK
14:24:07.885 > AT+CREG?
14:24:07.890 > 
14:24:07.891 > +CREG: 0,0
14:24:07.891 > 
14:24:07.892 > OK
14:24:08.142 > AT+CREG?
14:24:08.147 > 
14:24:08.147 > +CREG: 0,0
14:24:08.148 > 
14:24:08.148 > OK
14:24:08.399 > AT+CREG?
14:24:08.404 > 
14:24:08.404 > +CREG: 0,0

felmue

Hello @cocoa

from the output +CREG: 0,0 it looks like your modem is not registered to the network. According to the AT commands documentation, the second 0 in that answer means:

0 not registered, MT is not currently searching for an operator to register to

You could try to manually issue a 'AT+CEREG?' command to see if that yields any better result. Like I mentioned above, 'AT+CREG' didn't work for me either.

The other AT command to see if the modem is actually connected or not is AT+COPS?.

If you get something like this: +COPS: 1,2,"22801",9 it means your modem is connected. If you get: +COPS: 0 it is not connected.

Thanks
Felix

cocoa

Hello @felmue,

An interesting fact:

If I load the sample code you indicated the led of the modem continues to flash quickly without ever stopping , so it is correct to say that the modem is not connected .
If I erase the flash with the executable and restart the Atom DTU the modem after a few seconds connects autonomously with the cellular network.

Therefore there is something in the source code of the http example that prevents the modem from connecting.

cocoa

Hello @felmue,

I think use AT+CREG? maybe it's not correct for NB-IoT connection on LTE technology.

Should the modem probably use AT+CEREG? .

What do you think? Should something be changed in TinyGSM?

Thx.

felmue

Hello @cocoa

actually I changed my fix to include sms only roaming state e.g. 7 like this:

//        return (s == REG_OK_HOME || s == REG_OK_ROAMING || s == REG_OK_SMS);
        return (s == REG_OK_HOME || s == REG_OK_ROAMING || s == REG_OK_SMS || s == REG_OK_SMS_ROAMING);

The reason for that is that it seems to be a valid state for NB-IoT.

"7 Registered for "SMS only", roaming (applicable only when <Act>
indicates NB-IOT"

BTW: I've created a PR to that effect.

Thanks
Felix

cocoa

Hello @felmue ,

I changed the header by inserting your change, but behavior uk the same of the previous on.

I edited the file using CEREG instead of CREG.

Something has changed but it is not yet possible to run the http example.

11:51:23.983 > AT+CICCID
11:51:23.983 > 
11:51:23.983 > ERROR
11:51:23.983 > CCID: ERROR
11:51:23.983 > AT+CSQ
11:51:23.988 > 
11:51:23.989 > +CSQ: 24,0
11:51:23.989 > 
11:51:23.989 > OK
11:51:23.989 > Signal quality: 24
11:51:23.990 > Initializing modem...
11:51:23.990 > [  1689][E][esp32-hal-gpio.c:102] __pinMode(): Invalid pin selected
11:51:23.996 > E (1581) gpio: gpio_set_level(227): GPIO output gpio_num error
11:51:24.297 > E (1882) gpio: gpio_set_level(227): GPIO output gpio_num error
11:51:29.297 > AT
11:51:29.300 > 
11:51:29.300 > OK
11:51:29.300 > ATE0
11:51:29.304 > 
11:51:29.304 > OK
11:51:29.304 > AT+CFUN=1
11:51:29.311 > 
11:51:29.312 > OK
11:51:29.312 > AT+QCLEDMODE=1
11:51:29.316 > 
11:51:29.316 > OK
11:51:29.317 > AT+CMEE=0
11:51:29.320 > 
11:51:29.321 > OK
11:51:29.321 > AT+CTZR=0
11:51:29.325 > 
11:51:29.325 > OK
11:51:29.325 > AT+CTZU=1
11:51:29.329 > 
11:51:29.329 > OK
11:51:29.329 > AT+CPIN?
11:51:29.335 > 
11:51:29.335 > +CPIN: READY
11:51:29.336 > 
11:51:29.337 > OK
11:51:29.337 > Waiting for network...
11:51:29.337 > AT+CEREG?
11:51:29.343 > 
11:51:29.343 > +CEREG: 0,5
11:51:29.344 > 
11:51:29.344 > OK
11:51:29.344 > success
11:51:29.344 > AT+IPADDR
11:51:29.352 > 
11:51:29.352 > +IP ERROR: Network not opened
11:51:29.355 > 
11:51:29.355 > ERROR
11:51:29.355 > Device IP address: 
11:51:29.355 > success
11:51:29.356 > Performing HTTP GET request... AT+CIPCLOSE=0
11:51:29.363 > 
11:51:29.364 > +CIPCLOSE: 0,4
11:51:29.365 > 
11:51:29.365 > ERROR
11:51:29.365 > AT+CIPRXGET=1
11:51:29.371 > 
11:51:29.371 > OK
11:51:29.371 > AT+CIPOPEN=0,"TCP","api.m5stack.com",80
11:51:29.382 > 
11:51:29.382 > +CIPOPEN: 0,2
11:51:29.383 > failed to connect
11:51:39.383 > Performing HTTP GET request... 
11:51:39.383 > ERROR
11:51:39.433 > AT+CIPCLOSE=0
11:51:39.440 > 
11:51:39.440 > +CIPCLOSE: 0,4
11:51:39.441 > 
11:51:39.441 > ERROR
11:51:39.442 > AT+CIPRXGET=1
11:51:39.447 > 
11:51:39.448 > OK
11:51:39.448 > AT+CIPOPEN=0,"TCP","api.m5stack.com",80
11:51:39.458 > 
11:51:39.458 > +CIPOPEN: 0,2
11:51:39.459 > failed to connect
11:51:49.460 > Performing HTTP GET request... 
11:51:49.461 > ERROR
11:51:49.510 > AT+CIPCLOSE=0
11:51:49.517 > 
11:51:49.518 > +CIPCLOSE: 0,4
11:51:49.518 > 
11:51:49.519 > ERROR
11:51:49.519 > AT+CIPRXGET=1
11:51:49.524 > 
11:51:49.524 > OK
11:51:49.525 > AT+CIPOPEN=0,"TCP","api.m5stack.com",80
11:51:49.535 > 
11:51:49.535 > +CIPOPEN: 0,2
11:51:49.536 > failed to connect
11:51:59.537 > Performing HTTP GET request...

felmue

Hello @cocoa

if you want to use NB-IoT mode I found you'll need to un-comment the define in TinyGsmClientSIM7028.h line 32 as well.

#define MODE_NB_IOT      //Comment this macro definition when using CAT mode

BTW: CAT mode (e.g. not NB-IoT mode) works for me too.

Thanks
Felix

cocoa

@felmue It works in a totally random way, sometimes it gets the answer to the 'GET' and then it enters an infinite loop:

 AT+CIPRXGET=4,0
07:25:49.725 > 
07:25:49.727 > +CIPRXGET: 4,0,0
07:25:49.727 > 
07:25:49.727 > OK
07:25:49.727 > AT+CIPCLOSE?
07:25:49.734 > 
07:25:49.735 > +CIPCLOSE: 0,0
07:25:49.735 > 
07:25:49.735 > OK
07:25:50.219 > AT+CIPRXGET=4,0
07:25:50.226 > 
07:25:50.226 > +CIPRXGET: 4,0,0
07:25:50.227 > 
07:25:50.227 > OK
07:25:50.228 > AT+CIPCLOSE?
07:25:50.234 > 
07:25:50.234 > +CIPCLOSE: 0,0
07:25:50.236 > 
07:25:50.236 > OK
07:25:50.720 > AT+CIPRXGET=4,0
07:25:50.727 > 
07:25:50.728 > +CIPRXGET: 4,0,0
07:25:50.728 > 
07:25:50.728 > OK
07:25:50.728 > AT+CIPCLOSE?
07:25:50.736 > 
07:25:50.736 > +CIPCLOSE: 0,0
07:25:50.736 > 
07:25:50.737 > OK
07:25:51.221 > AT+CIPRXGET=4,0
07:25:51.229 > 
07:25:51.230 > +CIPRXGET: 4,0,0
07:25:51.230 > 
07:25:51.230 > OK
07:25:51.230 > AT+CIPCLOSE?
07:25:51.237 > 
07:25:51.237 > +CIPCLOSE: 0,0
07:25:51.238 > 
07:25:51.238 > OK
07:25:51.722 > AT+CIPRXGET=4,0
07:25:51.730 > 
07:25:51.731 > +CIPRXGET: 4,0,0

However, the library must be modified to be able to obtain a communication as it does not connect with the original commands.
I think the nb-iot command set in LTE is wrong.

It is also my opinion that an nb-iot device without a hardware reset cannot be used seriously.

Thanks for the helping.